Folding USB flash memory device for providing memory storage capacity

ABSTRACT

A USB flash memory device connected to a USB bus includes a flash memory module including at least one flash memory, a USB connector for transferring data packets onto the USB bus and receiving the data packets from the USB bus, a USB controller for controlling the USB connector according to the data packets and for controlling storage of data in and retrieval of data from the flash memory module, a display controller for storing memory storage capacity information of the flash memory module in a usage display register, a display window for displaying a value that is based on the content of the usage display register, and a power unit for supplying a power to the USB flash memory device. The USB connector is configured to be coupled to the USB bus. The USB flash memory device further includes a folding portion which is proximal to the USB connector and enables the USB flash memory device to be folded. According to the present invention, data storage information of the USB flash memory device and additional information such as current time and data storage time can be visually determined through the display window, even in cases where the USB flash memory device is not coupled to the host platform. Further, the folding portion of the USB flash memory device enhances space usability and efficiency.

FIELD OF THE INVENTION

[0001] The present invention relates to a portable data storage deviceand, more particularly, to a USB flash memory device including anon-volatile memory device for providing memory storage capacity.

BACKGROUND OF THE INVENTION

[0002] Conventional data storage devices generally fall into twocategories. The first category is electronic, solid-state memory devicessuch as read only memory (ROM) and random access memory (RAM). Thesememory devices are generally fixed within a computer. They are notintended to be removable or portable so that they may be used ondifferent computers to permit the transfer of data from one computer toanother computer.

[0003] The second category is surface-based data storage devices inwhich data is stored, typically, on the surface of a disk or tape.Examples of surface storage devices are magnetic disks, CD-ROMs, and USBdisks coupled externally to the computer through a mechanical drivemechanism to be installed in, or coupled to, the computer. Accordingly,the magnetic disks or CD-ROMs are removable and portable.

[0004] The USB disk includes a flash memory device therein to storereal-time data, voice, and audio and video data. An example of the USBdisk is disclosed in U.S. Pat. No. 6,148,354. FIG. 1 is a re-creation ofFIG. 5 of the above patent and shows a computer host system having a USBflash memory device.

[0005] Referring to FIG. 1, a flash memory system 42 includes a hostplatform 44 for operating a non-volatile USB flash memory storagedevice. The host platform 44 is connected to a USB flash memory device46 through a USB cable 48 and is connected to the USB cable 48 through aUSB host connector 50. The USB flash memory device 46 is connected tothe USB cable 48 through a USB flash device connector 52. The hostplatform 44 includes a USB host controller 54 for controlling andmanaging USB transmission on a USB bus. The USB flash memory device 46has a USB flash memory device controller 56 for controlling the USBflash memory device 46 and for managing the interface with the USB flashmemory device 46 and USB bus, the USB flash memory device connector 52,and at least one flash memory module 58. Preferably, the flash memorymodule 58 includes a flash memory module array in which data is stored.

[0006] When the USB flash memory device 46 is coupled to the hostplatform 44, a standard USB process is established. During the USBprocess, the host platform 44 configures the arrangement of the USBflash memory device 46 and the data transfer mode with the USB flashmemory device 46. During the course of the configuration, the hostplatform 44 determines the overall storage capacity of the USB flashmemory device 46 and determines the remaining, unused, capacity. In thismanner, information related to the storage capacity of the USB flashmemory device 46 is determined by directly connecting the USB flashmemory device 46 to the USB host connector 50 of the host platform 44.

[0007] Unfortunately, the above conventional method of perceiving thedata storage capacity of the USB flash memory device 46 hasdisadvantages in that it is required that the computer system of thehost platform 44 must be powered up and the USB flash memory device 46must be connected to the USB host connector 50 for determining storagecapacity information of the flash memory device 46.

SUMMARY OF THE INVENTION

[0008] The present invention is directed to a USB flash memory device inwhich data storage capacity can be perceived in a manner that overcomesthe disadvantages of the conventional approaches. In particular, datastorage capacity can be perceived independent of a host computer system.

[0009] A feature of the present invention is to provide a USB flashmemory device for providing memory storage capacity.

[0010] Another feature of the present invention is to provide a flashmemory device for providing memory storage capacity.

[0011] Still another feature of the present invention is to provide afolding USB flash memory device.

[0012] According to an aspect of the present invention, a USB flashmemory device for displaying a memory storage capacity includes a flashmemory module including at least one flash memory, a USB controller forcontrolling storage of data in and reading of data from the flash memorymodule, a display controller for storing the memory storage capacityinformation of the flash memory module in a usage display register, adisplay window for displaying a value that is based on the content ofthe usage display register, and a power unit for supplying power to theUSB flash memory device.

[0013] Preferably, the flash memory includes a data storage area inwhich a plurality of flash cells are disposed in a matrix of rows andcolumns and a state storage area storing a last address used in the datastorage area. The display controller includes the usage display registerand further includes a controller for receiving a last used address fromthe flash memory module and comparing the last used address with theoverall capacity of the flash memory module to determine the memorystorage capacity information, and a multiplexer for selectivelyoutputting the value that is based on the content of the usage displayregister or an output of the USB controller to be transmitted by thedisplay window. The usage display register may be directly controlled bythe USB controller. The USB controller calculates the memory storagecapacity of the flash memory module when returning from a power-downmode or when the power unit of the USB flash memory module is turned on.The display window further displays current time, data storage time, anddata transfer. The display windows display the memory storage capacityin a graphic manner or in a textual manner.

[0014] According to another aspect of the present invention, a flashmemory device includes a data storage area in which a plurality of flashcells are disposed in a matrix of rows and columns and a state storagearea storing a last used address of the data storage area. The last usedaddress can be stored in a register of the stage storage area.

[0015] According to still another aspect of the present invention, a USBflash memory device includes at least one flash memory device forstoring data, a USB connector for transferring data packets onto a USBbus and for receiving data packets from the USB bus, and a foldingportion for enabling the USB flash memory device to be folded. The USBconnector is configured to be coupled to the USB bus, and the foldingportion is disposed proximal to the USB connector.

[0016] According to yet another aspect of the present invention, a USBflash memory device includes a flash memory module including at leastone flash memory, a USB connector for transferring data packets onto theUSB bus and receiving the data packets from the USB bus, a USBcontroller for controlling the USB connector according to the datapackets and controlling storage of data in and reading of data from theflash memory module, a display controller for storing a memory storagecapacity information of the flash memory module in a usage displayregister, a display window for displaying a value that is based on thecontent of the usage display register, a power unit for supplying apower to the USB flash memory device, and a folding portion for enablingthe USB flash memory device to be folded. The USB connector isconfigured to be coupled to the USB bus, and the folding portion isdisposed proximal to the USB connector.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The foregoing and other objects, features and advantages of theinvention will be apparent from the more particular description ofpreferred embodiments of the invention, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

[0018]FIG. 1 is a block diagram of a conventional USB flash memorydevice.

[0019]FIG. 2 is a block diagram of a USB flash memory device accordingto an embodiment of the present invention.

[0020]FIG. 3 is a circuit diagram of a display controller of the USBflash memory device of FIG. 2.

[0021]FIGS. 4A and 4B show the display window of the device of FIG. 2.

[0022]FIG. 5 is a perspective view of a USB flash memory deviceaccording to another embodiment of the present invention.

[0023]FIG. 6 is a side view of the USB flash memory devices of FIG. 1and FIG. 5 as connected to a personal computer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] A USB flash memory device and a host platform according to anembodiment of the present invention are illustrated in FIG. 2.

[0025] Referring to FIG. 2, a host platform 100 and a USB flash memorydevice 200 are connected through a USB cable 300. The host platform 100includes a USB host controller 110 and a USB connector 120. The USBflash memory device 200 includes a USB connector 210, a USB controller220, a memory controller 230, a flash memory module 240, a displaycontroller 250, a display window 260, and a power unit 270.

[0026] The host platform 100 issues commands and requests to the USBflash memory device 200 to provide a service from the USB flash memorydevice 200 for the USB host controller 110. Typically, the host platform100 is in the form of a computer, a digital camera, an electronicnotebook, a personal digital assistant (PDA), a camcorder, a digital TV,and the like. The USB host controller 110 transfers data packets ontothe USB cable 300. The packets are received by the USB controller 220via USB connector 210. The USB controller 220 performs a variety ofoperations such as reading, writing, and erasing data to and from theflash memory module 240, and supports basic USB functionality such asdevice enumeration or configuration in the USB flash memory device 200.The USB controller 220 is connected to the flash memory module 240through the memory controller 230.

[0027] The flash memory module 240 includes at least one flash memorydevice in which typically NAND flash cells or NOR flash cells arearranged. The flash memory module 240 is connected to the USB controller220 through an address/data bus 235 and the memory controller 230. TheUSB controller 220 sends power signals and various control signals forcontrolling the flash memory module 240 to the flash memory module 240through a system bus 225. Such signals may comprise, for example, a chipselecting signal, a reading signal, and a writing signal. The flashmemory module 240 reads, writes (stores), and erases data in response tothese signals. Assuming the flash memory module 240 includes, forexample, two memory modules of 60Mbits each, an address translationtable for addressing the memory at the host platform 100 is embedded inthe flash memory module 240 and address mapping is performed through thememory controller 230. All commands and return codes between the hostplatform 100 and the USB flash memory device 200 are transmitted via aUSB data packet and are sent through the USB cable 300.

[0028] While writing data to the flash memory module 240, the lastoccupied address is stored in flash memories of the USB controller 220and the flash memory module 240. The USB controller 220 calculates andcompares the last address stored with the overall memory capacity of theflash memory module 240 and stores the result of the comparison in ausage display register. The memory storage capacity represents, forexample, the amount of memory capacity that is currently used and howmuch usable memory capacity remains. The content of the usage displayregister is transmitted to a display window 260 through a displaycontroller 250. In one application, the USB controller 220 transmits thevalue of the usage display register to the display window 260 inresponse to a command received by the USB host controller 110 thatrequests the amount of memory capacity that remains in the flash memorymodule 240. In addition, this same information can be transmitted to theUSB host controller via the USB cable according to the conventionalmeans described above.

[0029] In the event that the power unit 270 of the USB flash memorydevice is cut off, to thereby make it impossible to determine the memorystorage capacity of the device, the last address stored in the flashmemory of the flash memory module 240 is used to determine the memorystorage capacity when the USB flash memory device 200 is coupled to theUSB connector 120 of the host platform 100, as in the conventionalapproach.

[0030] According to another embodiment, the flash memory is partitionedinto a data storage area and a state information area. Data is writtento the flash memory in the data storage area, and the same informationas data storage information stored in the usage display register of thedisplay controller 250 is stored in the state information area. In thismanner, the memory capacity related information is stored and retrievedfrom the flash memory device itself.

[0031] The display controller 250 is now explained in detail withreference to FIG. 3.

[0032] Referring to FIG. 3, the display controller 250 includes acontrol circuit 310, a usage display register 320, and a multiplexer(MUX) 330. The control circuit 310 receives memory use information,e.g., the last address used, from the non-volatile memory in the flashmemory module (240 of FIG. 2) when a power unit (270 of FIG. 2) isturned on or when a USB flash memory device (200 of FIG. 2) is releasedfrom a power-down mode. Thereafter, the control circuit 310 compares thememory use information with the overall memory capacity of the unit, andstores the memory use information in the usage display register 320,since, in the absence of power to the display controller 250, theprevious value of the usage display register 320 is erased or lost. Themultiplexer 330 controls the data to be displayed, selecting either adata DIN from an external input or the data of the usage displayregister in response to a selection signal SEL generated by the controlcircuit 310.

[0033] The display window 260 of FIG. 2 may display data storageinformation such as the overall memory capacity of the flash memorymodule 240, used memory capacity, and usable memory capacity, as well asadditional information such as current time, data storage time, and datatransfer information.

[0034] The display window 260 is now explained in further detail withreference to FIG. 4A and FIG. 4B. In the example of FIG. 4A, informationis displayed graphically using an LED array. In the example of FIG. 4B,textual information is displayed on a 2-D array of pixels, for exampleon a liquid crystal display (LCD). Any of a number of techniques can beemployed to achieve visual representation of the data.

[0035] In one embodiment, the power unit 270 of FIG. 2 is an independentpower unit for supplying power to the USB flash memory device 200. Whenthe power unit 270 is turned on, power is selectively supplied to theUSB controller 220, the memory controller 230, the flash memory module240, the display controller 250, and the display window 260 in the USBflash memory device 200. Therefore, as previously stated, it is possibleto determine memory storage capacity information of the USB flash memorydevice 200, even in a case where the USB flash memory device 200 is notconnected to the USB connector 120 of the host platform 100.

[0036] In this manner, the USB flash memory device of the presentinvention may convey memory usage information through a display windowand provide additional information such as current time, data storagetime, and data transfer information without being installed at the hostplatform 100.

[0037] A perspective view of the USB flash memory device 200 accordingto the present invention is illustrated in FIG. 5. Referring to FIG. 5,the body of the USB flash memory device 200 may include a foldingportion 400, such as a hinge, that is disposed near the USB connector210. In this manner, the body of the USB flash memory device 200 can befolded at the folding portion 400.

[0038] Assuming the host platform 100 to be, for example, a personalcomputer, as illustrated at the left diagram of FIG. 6, a conventionalmemory device 46 is inserted into a USB port disposed at the rear sideof a personal computer body. Generally, the length of the USB flashmemory device 46 is about 10 cm. In the case where the personal computerbody is proximal to the surface of a wall, it must be spaced apart fromthe surface of the wall at least a distance equal to the length of theUSB flash memory device 46. However, according to the present invention,the USB flash memory device 200 including a folding portion 400 enhancesspace usability and efficiency because the personal computer body can bemore closely positioned relative to the surface of the wall by foldingthe folding portion 400, as illustrated in the right diagram of FIG. 6.

[0039] While this invention has been particularly shown and describedwith references to preferred embodiments thereof, it will be understoodby those skilled in the art that various changes in form and details maybe made herein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A USB flash memory device for displaying a memory storage capacity, comprising: a flash memory module including at least one flash memory; a USB controller for controlling storage of data in and reading of data from the flash memory module; a display controller for storing memory storage capacity information of the flash memory module in a usage display register; a display window for displaying a value that is based on a content of the usage display register; and a power unit for supplying power to the USB flash memory device.
 2. The USB flash memory device of claim 1, wherein the flash memory includes a state storage area in which the content of the usage display register is stored.
 3. The USB flash memory device of claim 1, wherein the display controller includes the usage display register and further comprising: a controller for receiving a last used address from the flash memory module and comparing the last used address with an overall capacity of the flash memory module to determine the memory storage capacity information; and a multiplexer for selectively outputting the value that is based on the content of the usage display register or an output of the USB controller to be transmitted by the display window.
 4. The USB flash memory device of claim 3, wherein the usage display register is directly controlled by the USB controller.
 5. The USB flash memory device of claim 1, wherein, upon returning from a power-down mode of the USB flash memory module, the USB controller determines the memory storage capacity information of the flash memory module.
 6. The USB flash memory device of claim 1, wherein when the power unit is activated, the USB controller determines the memory storage capacity information of the flash memory module.
 7. The USB flash memory device of claim 1, wherein the display window further displays current time, data storage time, or data transfer information.
 8. The USB flash memory device of claim 1, wherein the display window displays the memory storage capacity information using a graphic display.
 9. The USB flash memory device of claim 8, wherein the graphic display comprises an LED array.
 10. The USB flash memory device as recited in claim 1, wherein the display window comprises a liquid crystal display (LCD) window.
 11. A flash memory device comprising: a data storage area in which a plurality of flash cells are disposed in a matrix of rows and columns; and a state storage area storing a last address used of the data storage area.
 12. The flash memory device as recited in claim 11, wherein the state storage area includes a register storing the last address.
 13. A USB flash memory device comprising: at least one flash memory device for storing data; a USB connector for transferring data packets onto a USB bus and for receiving data packets from the USB bus, the USB connector being configured to be coupled to the USB bus; a folding portion for enabling the USB flash memory device to be folded, the folding portion being disposed proximal to the USB connector.
 14. A USB flash memory device, comprising: a flash memory module including at least one flash memory; a USB connector for transferring data packets onto a USB bus and for receiving the data packets from the USB bus, the USB connector being configured to be coupled to the USB bus; a USB controller for controlling the USB connector according to the data packets and for controlling storage of data in and reading of data from the flash memory module; a display controller for storing a memory storage capacity information of the flash memory module in a usage display register; a display window for displaying a value that is based on a content of the usage display register; a power unit for supplying power to the USB flash memory device; and a folding portion for enabling the USB flash memory device to be folded, the folding portion being disposed proximal to the USB connector.
 15. The USB flash memory device as recited in claim 14, wherein the flash memory includes: a data storage area in which a plurality of flash cells are disposed in a matrix of rows and columns; and a state storage area storing a last address used of the data storage area. 